Property data updating description Webcam chat stockholm
The Blog and Post classes both follow this convention. You can use the key annotation to specify which property is to be used as the Entity Key.
Entity Framework supports composite keys - primary keys that consist of more than one property.
Entity Framework refers to value objects as complex types. However as a property in the Blog class, Blog Details it will be tracked as part of a Blog object.
In order for code first to recognize this, you must mark the Blog Details class as a Complex Type.
That convention is to look for a property named “Id” or one that combines the class name and “Id”, such as “Blog Id”.
The property will map to a primary key column in the database. If code first does not find a property that matches this convention it will throw an exception because of Entity Framework’s requirement that you must have a key property.
That property can be created dynamically and does not need to be stored.
You can mark any properties that do not map to the database with the Not Mapped annotation such as this Blog Code property.
However, if your classes do not follow those conventions, you have the ability to add configurations to your classes to provide EF with the information it needs.
Many annotations let you specify an error message with the Error Message attribute.
Code first convention dictates that every property that is of a supported data type is represented in the database.
This article will focus on using Data Annotations (in the System. Data Annotations namespace) to configure your classes – highlighting the most commonly needed configurations.
Data Annotations are also understood by a number of . NET MVC which allows these applications to leverage the same annotations for client-side validations.
Search for property data updating description:
It’s not uncommon to describe your domain entities across a set of classes and then layer those classes to describe a complete entity.